Polymer coating for rubber articles

Abstract

The present invention is directed to the use of a polymer coating composition microbeads and a high Tg polymer with a Tg of greater than −10° C. for the inner coating on natural and synthetic rubber articles, particularly for latex gloves. The coating composition provides an inner surface coating that reduces friction between the latex and the hand to allow convenient donning. The coating composition is deliverable from an aqueous solution.

What is claimed is:  
     
         1 . An article comprising a formed natural or synthetic rubber article having directly deposited thereon a continuous coating of an aqueous-based coating composition comprising: 
 a) 0.1 to 10 percent by weight of a high Tg polymer, having a Tg of from −10° C. to +120° C.; and    b) 0.01 to 1 percent by weight of microbeads, said microbeads having an oil adsorption of less than 150 g/10 g powder.    
     
     
         2 . The article of  claim 1  wherein said high Tg polymer has a Tg of from 25 to 110° C.  
     
     
         3 . The article of  claim 1 , wherein said high Tg polymer comprises a (meth)acrylic emulsion polymer.  
     
     
         4 . The article of  claim 1 , wherein said coating composition further comprising a rheology modifier.  
     
     
         5 . The article of  claim 1  having no lubricating layer on top of the polymer coating composition.  
     
     
         6 . The article of  claim 1 , wherein the article is selected from the group consisting of gloves, prophylactics, catheters, balloons, tubing, and sheeting.  
     
     
         7 . The article of  claim 6 , wherein the article is a glove selected from the group consisting of surgeons' gloves, physicians' examining gloves, and workers' gloves.  
     
     
         8 . The article of  claim 1 , wherein the glove is powder-free.  
     
     
         9 . A method of making a glove comprising: 
 a) dipping a former into a liquid comprising a coagulant, removing the former from the coagulant and drying it to form a layer of coagulant on the former;    b) dipping the former into rubber latex and drying it to form a partially-cured rubber deposit on the former;    c) dipping the deposit of rubber into a dispersion comprising microbeads, and a high Tg polymer, and drying it to form a continuous polymer coating on the rubber deposit;    d) vulcanizing the deposit of rubber with the polymer coating in an oven at about 100° C. until the rubber is vulcanized to the desired degree and the layers are bonded to the rubber; and    c) cooling and then removing a finished glove from the said former.    
     
     
         10 . The method of claim  9 (a) wherein said liquid comprising a coagulant further comprises a mold release agent.  
     
     
         11 . The method of  claim 9 , further comprising after step (b) and before step (c), dipping the partially cured rubber deposit into water for sufficient time to remove at least some soluble proteins and other contaminants from the partially cured rubber deposit to form a leached partially cured rubber deposit.  
     
     
         12 . The method of  claim 9 , further comprising dipping the leached partially cured rubber deposit into a solution comprising a salt to improve the adhesion of the second layer of polymer coating composition to the partially cured rubber deposit.  
     
     
         13 . The method of  claim 12 , wherein the salt is sodium chloride.  
     
     
         14 . A method of making a glove comprising: 
 a) dipping a former into a liquid comprising a coagulant, removing the former from the coagulant and drying it to form a layer of coagulant on the former;    b) dipping the former into rubber latex and drying it to form a partially-cured rubber deposit on the former;    c) vulcanizing the deposit of in an oven at about 100° C. until the rubber is vulcanized to the desired degree and the layers are bonded to the rubber;    d) dipping the deposit of rubber into a dispersion comprising microbeads, and a high Tg polymer, and drying it to form a continuous polymer coating on the rubber deposit; and    d) cooling and then removing a finished glove from the said former.    
     
     
         15 . The method of claim  14 (a), wherein said liquid comprising a coagulant further comprises a mold release agent.  
     
     
         16 . The method of  claim 14 , further comprising after step (b) and before step (c), dipping the partially cured rubber deposit into water for sufficient time to remove at least some soluble proteins and other contaminants from the partially cured rubber deposit to form a leached partially cured rubber deposit.